Confirm 18f47k40 MSSP setting and allocation using PSS

[longpole001]

thats the question
the other question is , if you don't set a pin will spi2 still function

The answer from the testing is
1. Not Setting SS pin for ssp2 on the PPS does not appear to effect SSP2 running in this config
2. assigning SS on the PPS to portd.0 for SSP2 does not appear to effect SSP2 running or effect the I/O operation ( both in and out of Portd.0 ) , which was in use for other items

Cheers

Sheldon

[tumbleweed]

it turned out that the time taken to clear/set cs pin and the impost of two extra pins was as waste of resources an an unnecessary
complication. it works fine with out it

Yes, it works fine without it until it doesn't.

The SPI slave counts 8 clocks on SCLK in order to set BF to let you know you have a byte.
When the slave uses the SS input, that bit counter is reset when SS goes high. That keeps
you in sync with the master.

Without it, if there's ever a single glitch on the SCLK line the bit counter will be wrong and you can never resync master -> slave.
That also means that when you first power up, depending on who gets initialized first, there's a chance that the slave could see a transition on SCLK and you never get sync'd to begin with.

@Sheldon - I reread your requirements and I have to admit I'm not sure what you're trying to do.
If I read the comments correct you say that the slave isn't going to use data in. What would be the purpose of the slave?

[mpgmike]

Although usually not necessary, there is a PPS Unlock sequence that is missing in the above code:

PPSLOCK = $55
PPSLOCK = $AA
PPSLOCK.0 = 0

Also, I checked on available Ports for MSSP1/2 Functions and PORTB seems to work for all but SS; which A & D are the only usable PORTS for that. Just noting.

[richard]

@tumbleweed
although its sheldon's project the code is mine

If I read the comments correct you say that the slave isn't going to use data in. What would be the purpose of the slave?

neither spi port reads in any data . the purpose is to send two simultaneous bit streams synced by the same clock.
p10 led modules rgb or dual colour receive the pixel data per colour in that manner

it works fine without ss2

[tumbleweed]

the purpose is to send two simultaneous bit streams synced by the same clock

I see now what you're doing.

You're right, no SS needed. Sorry about the noise.

[richard]

You're right, no SS needed. Sorry about the noise.

its not noise, it was an issue that i initially considered and worth a mention.

the main issue for me was that mcc insists on a ss pin whether you configure to use it or not on that chip . i have not got a chip to
experiment with which left me unsure of what was required.